Answer:
3 Br₂(l) + I₂ (s) --> 2 IBr₃ (g)
Explanation:
After multiplying the coefficients and the subscripts, this would leave you with:
Reactants: 6 Br and 2 I
Products: 6 Br and 2 I
These are the lowest possible coefficients because you cannot further divide the coefficients and still get a whole number.